ui:repeat and POST

I'm struggling to use ui:repeat and can't figure out what the problem is. I wish to render several datatables dynamically like this

The display from this is correct. The problem arises when the form is posted: only the two first elements in the first list is updated in the bean, the rest is ignored. The post itself seems to be correct (I've looked at what was posted, and it contains all rows), but "pc.setLevel(Integer level)", which is set by the selectOneMenu is only called twice, when it should be called around a hundred times. Notice that this works perfectly if I remove the ui:repeat and replace the value of the datatable with #{bean.groups.get(0)} (thus only rendering the first table). It also works if I use JSTL c:forEach, but this is not a viable solution since my page relies on viewscope which is not compatible with c:forEach.

Have anyone seen this issue before? ui:repeat never seem to work well for me. Any answer would be greatly appreciated.